Laser Cut Blocks
by clothbot, published
Getting some designs laser cut and wondering what to do with the unused space? Why not fill it with something fun like Lego-compatible blocks?
Note: I have not confirmed these work. I just wanted to fill up some space on a heated build platform design I\'m hoping to send off to Ponoko shortly.
Update 2009/12/11: I uploaded the QCAD DXF (LCBlockFiller.20091210.dxf) and source SVG (LCBlockFiller.20091210.inkscape.svg) I sent off to Ponoko to figure out the service and exercise my QCAD+Inkscape design flow. QCAD calculates the total length of the "CuttingLines_0p003mm" layer geometry as 10931.7mm (~430.4"). Note: I created this file by laying down 8mm-spaced grid lines and placing peg outlines at the center of each so I wouldn't get double-counting of internal lines.
Update 2010/01/04: Test print from Ponoko arrived! I need to take some measurements and tweak designs to better accommodate the laser's kerf.
Disclaimer: LEGO is a trademark of the LEGO Group and these explorations are in no way associated with LEGO Group. Heck! The files are CC-licensed; nothing to stop them embracing and extending it themselves if they so chose! ;-)
Read the DXF into your favorite CAD program and sprinkle liberally in the empty spaces.
- Send to laser cutter.
The interlocking blocks should be cut from a material 3mm to be Lego-compatible at right-angles. Other blocks should be Lego compatible if cut from 3mm (~1/8"), 6mm (~1/4"), or 10mm (~3/8") thick material.
Important Note: You do want to keep the little inner ~5mm diameter cylinders.
- Place the cut-out block on a piece of real Lego-type block so the inner 5mm diameter cylinders pop out.
I shaped the cylinders/holes so the major diameter is 4.9mm to match real Lego peg dimensions and added little 0.05mm knobs around the periphery at 0, 90, 180 and 270 degrees.
- Pull the knobs out, rotate them 45 degrees and force them back into the hole.
Lego knobs are ~1.8mm high. Assuming the laser cutter kerf (the gap left by the vaporized material) isn\'t too wide the knobs should stay in place.
If friction isn\'t enough and they don\'t stick, a little dab of cyanoacrylate glue should do the trick.